Electric power plant



Se t. 5, 1933. L. c. FRANK 1,925,870

ELECTRIC POWER PLANT Filed Sept. 15, 1951 can I5 H F ts 27 T/9 U 1 I7 32 3 l43- 45 41 4s 33 I I HI WITNESSES: I104 INVENTOR [$0 C Frank.

Patented Sept. 5, 1933- UNITED STATES PATENT ()FFICE ELECTRIC rowEn PLANT Application September 15, 1931 Serial No. 562,885

13 Claims.

My invention relates generally to control systems for electric power plants andparticularly to plants that may be utilized for radio or wireless transmitting power service in isolated places, or

as a reserve unit where other sources of power are available.

In radio and wireless transmission, it is essen= tial that the voltage that is supplied to the transmitting equipment be substantially constant throughout the sending operations. This is particularly true with regards to the plate and filament voltages of the power tubes which comprise the essential parts of the sending equipment.

It is an object of my invention to provide for driving a starting motor of an internal combustion engine as a generator, after the cranking operations have ceased, to supply a voltage suitable for the filament circuits of a radio or a wireless transmitting equipment and for regulating the voltage thereof at a substantially constant value.

It is also an object of my invention to provide for generating a voltage suitable for the plate circuits of a radio or a wireless transmitting equipment, and for maintaining said generated volttage at a substantially constant value.

Another object of my invention is to provide for cranking an internal combustion engine and,

in case it fails to start or stalls, for discontinuing such cranking action in order to prevent the total discharge of the stored electrical energy that is utilized for cranking said engine.

A still further object of my invention is to provide for preventing the hunting action of a speed responsive device, as well as for maintaining the speed of an internal combustion engine substantially constant regardless of the load conditions.

A more specific object of my invention is to provide for so choking the carburetor of an internal combustion engine during the starting or warming-up period as to cause the choking effeet to vary from a maximum to a minimum in order to insure the proper feeding of a fuel mixture most suitable for quick starting.

Another object of my invention is to provide for, starting an internal combustion engine free of a load and for running it for a predetermined length of time in order to allow the engine to warm-up before the load is thrown on.

Other objects of the invention will hereinafter become apparent.

For a fuller understanding of the nature and the objects of my invention. reference should be had to the following detailed description taken in connection with the accompanying drawing, in

which a control system embodying the features of my invention is shown.

Referring more particularly to the drawing, my invention, in general, comprises an internal combustion engine 1o having a fiy-wheel 21 and a magneto 25 mechanically coupled to the engine.

A high voltage generator 22, having a separately excited field winding 23, and a low voltage dynamo-electric machine 11, both of which being disposed to supply power to the plate and the file-- ment circuits, respectively, of a radio or a wire less transmitting equipment, and a regulator 96 which provides for maintaining the voltage of the dynamo-electric machine 11 substantially constant at all times are also mechanicaHy coupled to the engine.

Preferably, as shown, the dynamo-electric machine 11 is provided with a starting series field winding 14, a running series field winding 15, and a shunt field winding 12 connected in series with an adjustable resistor 13.

For the cranking of the engine 10, the dynamoelectric machine 11 is connected in circuit with a source of electrical energy, such as a storage battery 16, and operated as a motor. After the engine starts and attains a predetermined speed, the dynamo-electric machine 11 operates as a generator to charge the battery 16 as well as to deliver power to the load conductors 94 and 95 which supply power to the filament circuits of the radio or the wireless transmitting equipment.

During the starting of the engine 10, the choke valve 45 is closed by the relay 47 by means of a connecting rod 46. The relay 47, in addition, provides for opening a set of contact members 53 and 54 by means of a pivotally mounted arm 51 which is disposed to depress the pivotally mounted arm 52 that carries the contact member 54 when the hook 50 of the relay is raised. The opening of the contact members 53 and 54 deenergizes the field winding 23 of the high voltage generator 22 in order that the engine 10 may be free of the load of the generator during the starting and warming-up period. 1

Just as soon as the arm 52 is depressed by the relay 4'], the free end oLthe thermostat 56 swings to the left and rides upon the top surface of the remote end of the arm 52. Accordingly, the ther- -mostat 56 prevents the spring 55 from biasing the contact member 54 against the contact member 53 notwithstanding the fact that the relay 47 may be open or deenergized.

However, after a predetermined length of time,

that is, after the engine has had suflicient time I to warm up, the heating element 58, which is simultaneously energized with the initiation of the cranking action, generates suflicient heat to cause the free end of the thermostat 56 to deflect to the right, beyond the end of the pivotally mounted arm 52, and thus permits the spring 55 to bias the contact 54 against the contact 53. In this manner, the generator 22 does not supply any power to the plate circuits of the radio or the wireless transmitting equipment until the engine warms up.

Since the choke valve 45 closes the air inlet conduit to the carburetor 34, a time limit or relief choke valve 18 that is disposed to gradually relieve the choking effect, is provided. As shown, the relief valve 18 is actuated by the free end of the bimetal thermostat 43 mounted in a compartment 42 and disposed adjacent to a heating element 44. Upon the initiation of the cranking operation, the heating element 44 is energized by the battery 16 and, as the cranking operation continues, the thermostat 43, under the influence of the heat generated by the heating element 44, gradually opens the relief choke valve 18. As is manifest, the cooperative action of the choke 45 and the relief valve choke 18 provides for choking the carburetor 34 during the warming-up period, so that the resultant choking effect varies from a maximum to aminimum. In this manner, a gradual increase of air is provided to the carburetor in order to effect the proper mixture for the starting of the engine 10. For a more detailed description of the choking action, as provided by the choke 45 and the relief choke valve 18, reference may be had to an application to Letters Patent, relating to a time limit-engine choking device, Serial No. 424,616, filed January 30, 1930, by me as co-inventor with D. J. Conant, and assigned to the assignee of this invention.

The thermal relay which includes two heating elements 83 and 84 and a bimetal thermostat 81, one end of which being mounted upon a stationary member 82, provides for discontinuing the cranking action in case the engine 10 fails to start for any reason whatsoever, such as for the lack of fuel. The heating elements 83 and 84 are energized by means of the battery '16 during the cranking operation and, after a predetermined length of time, in case the engine fails to start, they generate suflicient heat to cause the free end of the thermostat 81 to deflect upwardly to coincide with the opening 79 provided in the movable arm 80. When the free end of the thermostat 81, which normally constrains the movable contact member 64 against the stationary contact memcer 76, coincides with the opening '79, the spring '78 moves the movable contact member 64 from the stationary contact member 76 and against the stationary contact member 7'7, which energizes the signal alarm 106 to apprise the attendant that the engine failed to start. The opening of the contact members 64 and 76 deenergizes the dynamo-electric machine 11 which was previously operating as a motor to crank the engine, thereby preventing the total discharge of the storage battery 16.

When the engine starts, the speed thereof is determined by a relay 65 acting in cooperation with a flyball governor 28 that is' driven by the engine 10 by means of bevel gears 26 and 27. As illustrated, the plunger 6'7 of the relay 65 is connected to the governor 28 by means of a control rod 30 that is, likewise, connected to the throttle valve 32, and a pivotally mounted arm 29. The relay 65 is continuously energized during the starting and running periods and it provides a force for raising the plunger 67 which tends to close the throttle valve 32 but, as is manifest, the movements thereof are limited by the flyball governor 28. Therefore, as the speed of the engine increases, the ball weights 35 of the flyball governor move outwardly to permit the plunger 67 to bias the throttle 32 upward, that is, towards its closed position. This action causes the engine to slow down somewhat, as determined by the closing of the throttle valve 32 with the result that the ball weights 35 gradually move inwardly to oppose the force exerted by the plunger 6'7. Accordingly, the throttle 32 is biased towards its open position. In this manner, the relay 65 and the flyball governor 28 cooperate to control the throttle 32 for maintaining the speed of the engine at a substantially constant value regardless of the load conditions.

In this connection, I wish to point out that the dynamo-electric machine 11 generates a slightly higher voltage at a predetermined speed when cold than when hot because the resistance in the field windings is less, but at the same time the resistance of the winding of the relay 65 is correspondingly less, with the result that relay 65 exerts a slightly larger force to close the throttle of the engine when cold than when hot. Consequently, the manner in which I regulate the throttle valve 32 compensates for voltage variations caused by a change in resistance as a result of cold or hot conditions.

In order to insure that the hunting action, that is generally incident to speed responsive devices, such as the flyball governor 28, shall be reduced to a minimum, the plunger 67 is provided with a sleeve 68 that constitutes a shortcircuited turn. Therefore, the .movements of the plunger 67 caused by the hunting actions of the governor generate a short-circuited current in the sleeve 68. Consequently, the forces required to generate the short-circuited currents oppose the hunting actions normally incident to current responsive devices, such as the governor 28. In other words, the sleeve 68 provides a damping force for opposing the hunting actions of the governor and, in consequence, the throttling of the engine is materially improved over what it would be in the absence of a damping action as provided by the sleeve 68.

When the dynamo-electric machine 11 is driven as a generator to provide power to the filament load conductors 94 and 95 and to the battery 16 for recharging, the voltage thereof is maintained at a substantially constant value by means of the regulator 96. The regulator is of the vibrating type and its stationary contacts 101 and 102 and its movable contact 111 are connected in circuit with the shunt field winding 12 and the adjustable resistor 13 of the dynamoelectric machine, and an external resistor 103. As illustrated, the spring 98 normally biases the movable contact member 111 against the stationary contact member 101 to exclude the resistor 13 from the shunt winding 12. The energizing coils 99 and 100 of the regulator are connected in circuit with the armature of the dynamo-electric machine 11, so that the movable contact member 111 vibrates between the stationary contact member 101 and 102 in accordance with the variations of the armature current. V

The operation of the control system may be explained as follows:

In the position, as shown, the engine is stationary or inactive and the magneto 25 that provides the ignition for the engine is connected to the ground 17 through a conductor 166, the starting switch '74 which is shown in the stop position and a conductor 127.

When the starting switch '74 is actuated to the starting position, a circuit is established for energizing the relay 47 by the battery 16. At the same time, the ground on the magneto 25 is removed. The circuit that energizes the relay 1'? extends from the positive terminal of the battery 16 through a conductor 115, the heating element 33, conductor 116, a current limiting resistor 23, conductors 118 and 119. the movable arm 86 of the thermal relay '75, the contact members 64 and 76, conductors120 and 121, the contact member 66, the conductor 122, the magnetizing windings of the relay 4'7, conductors 123, 124, 125 and 126, the starting switch 74, the conductor 127 and the ground 17, to the negative side of the battery 16. Another circuit that provides for energizing the relay extends from the contact members 66 of the relay 65 through the magnetizing winding of the relay 65, conductors 124, 125 and 126, thestarting switch 74, the conductor 127-and the ground 17, to the negative side of the battery.

In addition, another circuit is energized for energizing the heating element 58. This circuit may be traced from the conductor 120, through a conductor 128, the contact members '71, a conductor 129, the heating element 58, conductors 125 and 126, the starting switch 74. the conductor 12? and the ground 17, to the negative side of the battery. Therefore, the closing of the starting switch '74 provides for energizing the relay 47, the relay 65 and the heating elements 58 and 83.

The operation of the relay 4'? provides for establishing circuits which energize the dynamoelectric machine 11 to cause it to act as a motor for cranking the engine 10, the heating element 44 of the choking device and the heating element 84.- of the thermal relay 75. The circuit for energizing the dynamo-electric machine 11 to cause it to act as a motor extends from the positive side of the battery 16 through a conductor 115, the heating element 83, a conductor 130, the contact members 48 of the relay 47, a conductor 131, the starting series field winding 14, a conductor 132, the armature of the dynamo-electric machine 11 and the ground 1'7 to the negative side of the battery. Since the winding 12 is connectedin shunt with the armature, current also .flows from the conductor 132 through the adjustable resistor 13, the winding 12 and the ground 17 to the negative side of the battery. Thus, the battery 16 is connected in circuit with the dynamo-electric machine 11 to cause it to operate as a motor for cranking the engine .16.

Simultaneously with the closing of the relay 4'1, a circuit is established through the contact members 49 for energizing both the heating elements 44 of the air inlet conduit 43 and the heating element 84 of the thermal relay '75. The circuit for energizing the heating element 44 extends from the contact members 49 through a conductor 133, the heating element 44 and to the ground 1'7. The circuit for energizing the heating element 84 extends from the contact members 49 through a conductor 134? the heating element 84 and the conductor 135 to the ground 1'7. Also, as shown;

a signfl alarm its, such as a bell is energized when the relay 4'?! closes in order to signal to the attendant that the engine is being cranked. This circuit extends from the conductor 134 through conductor 136, the alarm 105, the conductor 137 to the ground 17.

As hereinbefore mentioned, the relay 47 like wise mechanically actuates the choke 15, and depresses the pivotally mounted arm 52 which separates the contact members 53 and 54. The opening of the contact members 53 and .54 prevents energization of the field winding 23 of the generator 22.

Assuming that the engine fails to start as the result of the cranking operation, the heating elements 63 and 84 of the thermal relay 75, after a predetermined length of time, generate sufiicient heat to cause the free-end of the thermostat 81 to deflect upwardly. Just as soon as the end of the thermostat 81 coincides with the opening '19, it allows the spring 78 to move the movable contact member 64 from the stationary contact member 76 and against the contact member 17 with the result that the entire starting circuits are deenergized. When the movable contact member 64 touches the contact member '1'? a circuit is established for ringing an alarm signal 106, which apprises the attendant of the fact that the engine has failed to start. Before the engine can be cranked again, it is necessary for the attendant to reset the thermal relay '75. Accordingly, the thermal relay prevents the total discharge of the storage battery 16 in case the engine fails to start as a result of the cranking operation.

In this connection, when the normal starting current is flowing to crank the engine, the heat ing element 84 is designed to generate the greater portion of the heat tor deflecting the free end of the thermostat 81, since it is connected with full voltage across the battery, whereas the heating element83 is disposed to ofifer a slight amount of heat. However, the opposite is true when the rotor of the dynamo-electric machine is locked tor any reason whatsoever, as for example, the stick= ing of the engine. In the lock rotor condition, the voltage across the heating element as de= creases to a very low value and the armature current that flows through the heating element 62 increases to a very large value. Under this con-- dition, the heating element 83 provides substan-- tially all of the heat for deflecting the free-end of the thermostat 81 to coincide with the opening 79. Consequently, the thermal relay 75 provides for deenergizing the dynamo-electric machine 11 after a predetermined length of time either in case the engine fails to start or in case of a lock rotor condition.

Assuming the engine starts as a result of the cranking operation, the heating element 44 causes the thermostat 43 to gradually open the choke relief valve 18 which provides for gradually varying the choking action from a maximum to a minimum. The gradual variation of the choking action, as provided by the choke relief valve 18, allows the engine to gain speed very readily without sputtering and overloading. which it would do, were not the choking eifect minimized by the opening of the choke relief valve 18.

As the speed of the engine attains a predetermined value, the flyball weights 35 of the governor move outwardly to permit the plunger 67 of the relay to open the contact members 66. The opening of the contact members 66 interrupts the circuit that formerly energized the relay 47. The

deenergization of the relay 4'! disconnects the dynamo-electric machine, and the heating elements 44 and 84 from the battery 16. At the same time, the relay 47 actuates the choke 45 to running position and unlatches the pivotally mounted arm 52. Although the relay 47 has unlatched the pivotally mounted arm 52, the spring cannot move the contact member 54 against the stationary contact member 53 since the thermostat 56 is riding on the top surface of the end of the pivotally mounted arm 52. Therefore, the engine 10 is running free of the load of the high voltage generator 22 since the thermostat .56 prevents the operation of the relay 69 which energizes the field winding 23 of the generator 22.

However, the engine 10 is driving the dynamoelectric machine as a generator and just as soon as the generated current reaches a predetermined value it causes the reverse current relay 89 to close its contact members 92 thereby connecting the dynamo-electric machine 11 to the load conductors 94 and 95 and to the battery 16. The circuit for energizing the relay 89 may be traced from the positive terminal of the dynamo-electric machine through a conductor 132, the running series winding 15, the conductors 143 and 144, the winding 90, conductors 137 and 135 to the negative terminal of the dynamo-electric machine through the ground 17. The closing of the contact member 92 connects the positively energized conductor 143 to the load supply conductor 94 through a conductor 145, the winding 91, the contact members 92. The circuit Ior charging the battery 16 extends from the load conductor 94 through a limiting resistor 93, conductor 116, the heating element 83 and the conductor 115 to the positive side of the battery 16.

The operation of the reverse current relay 89 is such that, when the generated voltage of the dynamo-electric machine is higher than that of the battery, current flows through the coil 91 for establishing a flux that aids the flux of the coil for maintaining the contact members 92 closed. On the other hand, if the voltage gener-,

ated by the dynamo-electric machine is less than that of the battery, current flows through the coil 91 in the opposite direction and establishes a large flux for opposing the smaller fiux of the coil 90 and opens the contact member 92. The action of the reverse current relay 89 is such that the battery 16 will not discharge in case the voltage produced by the dynamo-electric machine is less than that of the battery. However, this condition never prevails unless the engine is running at very low speeds, since the regulator 96 maintains the voltage at a substantially constant value notwithstanding the speed of the engine 10.

The action of the regulator may be explained in the following manner: When the voltage that is generated by the dynamo-electric machine is below a predetermined value, the spring-pullis greater than the coil-pull and, therefore, biases the movable contact 111 against the stationary The closing of these contacts ex-, cludes the resistor 13 from the shunt field winding contact 101.

result that the current increases. If the voltage increases above a predetermined value, the coilpull of the regulator overcomes the spring-pull and separates the movable contact members 101 and 111. The separation of the contact members reconnects the. resistor 13in series with the winding 12 and thereby causes the generator to generate a lower voltage. Then, if the generated voltage decreases to a predetermined value, the

spring again moves the contact member 111 against the contact "member 101 and bridges the resistor 13 which causes the generated voltage to again increase. The frequency at which the contact members open and close depends upon the shunting required to maintain a constant generated current, or in other words, a constant potential across the load conductors 94 and 95.

However, in case the bridging of the resistor 13 is not sufiicient to keep the generated voltage from rising above a predetermined value, the coil-pull becomes still greater and causes the movable contact member 111 to swing down and vibrate against the stationary contact member 102. The closing of contact members 111 and 102- provides not only for connecting the resistor 13 in circuit with the field winding 12, but also for inserting the resistor 103 in parallel with the winding 12. The combined effect of the resistors 13 and 103 provides for further reducing the current traversing the field winding 12, with the result that the generated voltage is greatly reduced. The rate at which the contact member 111 vibrates against the contact 102 depends upon the shunting required to maintain a substantially constant voltage. Therefore, the action of the regulator 96 is such that the potential of the supply conductors 94 and which are disposed to be connected to the filament circuits of the radio or wireless transmitting equipment, is maintained substantially constant.

It will be observed under the stated conditions that the engine is running to cause the dynamoelectric machine 11 to operate as a generator to supply electric energy to the load conductors 94 and 95 as well as to charge the storage battery 16. A limiting resistor 93 is disposed between the load conductor 94 and the storage battery 16 in order to limit the charging current in case the voltage of the battery is materially lower than that existing between the load conductors 94 and 95.

From the foregoing description, it should be apparent that the engine 10 is running free of the load of the generator 22 since the thermostat 56-prevents the spring 55 from closing the contact members 53 and 54. In this connection, it

is desirable, from the operating standpoint, to delay the operation of the generator 22 until the motor 10 has sufficient time to warm up. This is particularly true, since the speed of the engine 10 may be irregular during the starting period and thereby cause the generator 22 to deliver an uneven voltage during the warmingup period. Therefore, after a predetermined length of time from the cranking of the engine 10, the heating element 58 generates sufllcient heat to cause the free-end of the thermostat 56 to move to the right, beyond the end of the pivotally mounted arm 52. The spring 55 now biases the contact member 54 against the contact member 53 and establishes a circuit for energizing the relay 69. This circuit extends from the positively energized conductor 154, through the contact members 53 and 54, the pivotally mounted arm 52, the conductor 155, the magnetizing winding of the relay 69, conductor 126, the starting switch 74, the conductor 127, to the ground 1'7.

The operation of the relay 69 interrupts the circuit for energizing the heating element 58 by opening the contact member 71, and at the same time connects the field winding 23 in circuit with the dynamo-electric machine 11. This field circuit may be traced from the positively energized conductor 143 through conductors 148 and 150, the adjustable resistor 151, conductor 152, the contact members '70 of relay 69, conductor 153, the field winding 23 and to the ground 17. The energization of the field winding 23 causes the generator to supply full voltage'to the conductors 36 and 37 that are disposed to be connected to the plate circuits of a radio or a wireless transmitting equipment.

In the interest of safety, a speed limit switch 108 that is driven by the engine 10 through an extended shaft from the generator 22 is pro vided to stop the engine in case its speed exceeds a predetermined value. As illustrated, when the speed of the engine exceeds a predetermined value, the centrifugal force of the bridging memher 110 overcomes the spring 109 and bridges its contact members which connects the magneto 25 to the ground 17. At the same time, a circuit is established for signaling the attendant that the plant has been shut-down by the over speed device. The signaling circuit may be traced from the positive terminals of the battery 16, through conductors 115 and 163, the alarm signal 107, the conductor 162, the contact members 110 and the conductor 164 to the ground 17.

I realize that various changes and modifications may be made in a system embodying my invention without departing from the spirit and scope thereof, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art or as are set forth in the appended claims.

I claim as my invention:

1. A control system comprising, in combination, an internal combustion engine, a dynamo electric machine connected to said engine, a generator having a field winding driven by said engine, a source of electrical energy, means for energizing the dynamo-electric machine'by said source to cause it to operate as a motor for cranking said engine, means responsive to a predetermined speed of the engine for discontinuing the cranking operation and for causing the dynamo-electric machine to act as a generator and tion and for causing said dynamo-electric ma-,

chine to operate as a generator and means for energizing said field winding by said dynamoelectric machine after a predetermined interval of time from the starting of said engine.

3. A control system comprising, in combination, an internal combustion engine, a dynamoelectric machine connected to said engine, a generator having a field winding driven by said engine, means for operating the dynamo-electric machine as a motor for cranking said engine,

means responsive to a predetermined speed of said engine for discontinuing said cranking action and for causing said dynamo-electric machine to operate as a generator, thermostatically operated means including a heating element for connecting the said field winding in circuit with said dynamo-electric machine and means for energizing said heating element.

4. A control system comprising, in combination, an internal combustion engine, a dynamoelectric machine connected to said engine, a generator having a field winding driven by said engine, means for operating the dynamo-electric machine as a motor for cranking said engine, means responsive to a predetermined speed of said engine for discontinuing said cranking action and for causing said dynamo-electric machine to operate as a generator, a heating element, means responsive to the temperature of the heating element for connecting the said field winding in circuit with said dynamo-electric machine, means for simultaneously energizing said heating element with the cranking of said engine and means for deenergizing said heating element when said temperature responsive means operates:

5. A control system comprising, in combination, an internal combustion engine having a carburetor, a'dynamo-electric machine connected to said engine, an air conduit for said carburetor, a heating element for said conduit, a source of electrical energy, a choke valve for said conduit, a relay energized from said source for mechanically actuating said choke valve and for connecting said dynamo-electric machine and said heating elements in circuit with said electrical source, said dynamo-electric machine acting as a motor to crank said engine and means responsive to the speed of the engine for deenergizing said relay.

6. Agcontrol system comprising, in combination, an internal combustion engine having a carburetor, a dynamo-electric machine connected to said engine, an air conduit for said carburetor, a heating element for said conduit, a source of electrical energy, a choke valve for said conduit, a relay for mechanically actuating said choke valve and for connecting said dynamo-electric machine and said heating elements in circuit with said electrical source, said dynamo-electric machine acting as a motor to crank said engine, means including thermostatically operated contact members for connecting said relay in circuit with said source, a second heating element energized from said electrical source for affecting said thermostatically operated contact members, said contact members being actuated to open position when the temperature of the second heating element attains a predetermined value, thereby deenergizing said relay.

7. A control for regulating the speed of an internal combustion engine having a carburetor comprising, in combination, a throttle valve for regulating the speed of the engine, a governor responsive to the speed of the engine, a plunger actuated by a solenoid and connected to said governor and said throttle valve, a current conducting sleeve carried by said plunger for opposing the hunting action of the governor.

8. A control for regulating the speed of an internal combustion engine having a carburetor comprising, in combination, a throttle valve for regulating the speed of the engine, electromagnetic means for actuating said throttlevalve, means responsive to the speed of the engine for limiting the movements of said throttle caused by said electromagnetic means and means carried by said electromagnetic means for opposing the hunting actions of the said speed responsive means. I

9. A control for regulating the speed of an internal combustion engine having a carburetor comprising, in combination, a throttle valve for regulating the speed of the engine, means including a relay for controlling the cranking of the engine, a relay having an armature connected to said throttle, means responsive to the speed of the engine for controlling the movements of the armature of said second mentioned relay, thereby regulating the speed of the engine and means responsive to a predetermined distance of travel of the armature for controlling the operation of the means for controlling the cranking of the engine.

10. A control for regulating the speed of an internal combustion engine having a carburetor comprising, in combination, a throttle valve for regulating the speed of the engine, means including a relay for controlling the cranking of the engine, a relay having an armature connected to said throttle, means responsive to the speed of the engine for limiting the movements of said armature, thereby regulating the speed of the engine and means responsive to a predetermined distance of travel of the armature to control said first named means to effect stopping of the said cranking action and means carried by the armature of the relay for opposing the hunting action of the speed responsive means.

11. A control system comprising, in combination, an internal combustion engine, a dynamoelectric machine having a field winding connected to said engine, a source of electrical energy, means for connecting said dynamo-electric machine in circuit with said electrical source for cranking said engine, means responsive to the speed of the engine for discontinuing said cranking action and for causing said dynamo-electric machine to operate as a generator, a regulator connected in circuit with said field winding for causing the dynamo-electric machine to develop a substantially constant voltage when acting as a generator, means including a limiting resistor for connecting the electrical source in circuit with the dynamo-electric machine when acting as a generator to store up electrical energy.

12. A control system comprising, in combination, an internal combustion engine, a generator having a field winding driven by said engine, means for starting the engine, means actuated by part of said starting means for deenergizing said field winding and thermal means for energizing said field winding after a predetermined time interval from the starting of said engine.

' 13. A control system comprising, in combination, an internal combustion engine, a dynamoelectric machine connected to said engine, a generator having a field winding driven by said engine, means for energizing said dynamo-electric machine to cause it to operate as a motor for cranking said engine, means for discontinuing said cranking action and for causing said dynamo-electric machine to operate as a generator, thermal means for connecting said field winding in circuit with said dynamo-electric machine after a predetermined time interval from the starting of said engine, a regulator connected in circuit with said dynamo-electric machine to cause it to deliver a substantially constant voltage to said generator field winding.

LEO C. FRANK. 

